Although the immune deficiency syndrome (AIDS) is characterized by the appearance of severe often fatal opportunestic infections and epidemiological studies suggest that some virus like microorganism is involved in the genesus of the condition no agent has as yet been incriminated in the etiology of the disease. Because of the pathology seen in a number of known parvovirus infections, such as feline panleukopenia, neonatal mouse infection with immunosuppressive strains of minute virus of mice (MVM), and human infection with the B19 virus, recently shown to be responsible for aplastic crises and erythema infectiosum in children, as well as the timely appearance of a new fatal virus disease in dogs caused by a parvovirus, these agents need to be examined in great detail. The specific goal of this project is to determine the distribution of antibody and/or antigen to known parvoviruses in control as well as at risk for AIDS populations using standard serological techniques already developed within this laboratory.